Conventional windshields commonly have a structure in which a front cowl is disposed on a front portion of a motorcycle and includes a screen, otherwise known as a windshield, secured thereto for forward view. This screen protects the rider from running wind, rainwater, and dust. However, the running wind which passes over the screen can generate negative pressure behind the screen, which creates swirling currents in the face of the rider and also right behind the rider. The swirling currents can increase drag as well as make the driver uncomfortable. To solve this problem an air inlet port can be provided in a lower portion of the screen so that air taken in from the air inlet port can be channeled between the screen and an air guide plate disposed behind the screen. The air channeled behind the screen can be joined with the air in front of the screen to prevent negative pressure that causes swirling currents that make the rider uncomfortable.
Incidentally, while the above-mentioned air inlet port reduces negative pressure, it also allows rainwater to be channeled behind the screen. Hence, a ridge to block rainwater from reaching the rider can be formed on the air guide plate. The rainwater accumulated on the air guide plate can be gathered to be discharged from a drain formed on the air guide plate (see JP 02-33794).
However, in the foregoing conventional windshield, although rainwater can be blocked from going backward by means of the ridge formed on the air guide plate, the ridge generates unpleasant hissing noises as air passes over the ridge.
In addition, since the drain used to discharge rainwater is formed on the air guide plate, the functional parts inside the air guide plate can be seen through the drain, thereby degrading the appearance of the motorcycle.
This present invention provides a windshield unit for a motorcycle which can, without damaging the motorcycle's appearance, reduce hissing noises and improve water discharge.